Study On Synthesis Of The Secondary Amines By One-Pot And Riboflavin

The thesis is composed of two parts:In part one, the catalytic synthesis of the secondary amines and intrinsic kinetics of the imine had been studied. Firstly, the characters, functions, the industrial situations and development trends and the synthesis methods of the secondary amines were reviewed. The development orientation and research highlight had been pointed out.Using the Raney nickel as catalyst, N-benzyl-4-methylbenzenamine was synthesized from 4-Nitrotoluene and benzaldehyde by one-pot catalytic hydrogenation in low-pressure and mild temperature. The optimal reaction conditions were that: the hydrogen pressure 1.0 MPa; reaction temperature 353K; reaction time 90 min. Under the selected conditions, the yield of N-benzyl-4-methylbenzenamine is about 100%. By changing the reaction conditions, a few secondary amines were synthesized.The reaction mechanism of preparation of N-benzyl-4-methyl-benzenamine by catalytic hydrogenation for 4-nitrotoluene and benzaldehyde and the intrinsic kinetics of the imine catalytic hydrogenation had been studied. It was confirmed that the reaction mechanism of the prapartion of N-benzyl-4-methyl-benzen- amine by one-pot was ordinal, that was (1) hydrogenation of the nitryl, condensation and dehydration of the aniline with benzaldehyde;(2) hydrogenation of the imine. According with the experimental datas, the intrinsic kinetic equation could be confirmed as: The apparent activation energy was E=34.57kJ/mol and heat of hydrogen adsorption was 42.24 KJ/mol.In the part two, the research of green chemical synthetical technology of riboflavin was carried out. The key intermediate N-(D-ribose)-3,4 -Dimethyl- aniline was synthesized by one-pot from D-ribose and 3,4-Dimethylaniline. By optimizing technology conditions, the optimum conditions were that about 5% content of the catalyst at 353-363K and the 1.0 MPa for hydrogen pressure. Under the conditions, the yield was about 95%.The effect of ratio of the reactants and reaction temperature on synthesis of 4,5-dimethyl-N-(D)-RIbityl-2-(phenylazo)-aniline from benzenediazonium sulphate and N-(D-ribose)-3,4-Dimethylaniline was obvious. The experiment results showed that the optimum conditions were reaction temperature -5℃and ratio of reactants 1.8.By the time, preparation of riboflavin was researched by condensation of 4,5-dimethyl-N-(D)-RIbityl-2-(phenylazo)-aniline with barbituric acid. Several factors such as solvent, acid catalyst, reaction temperature and so on were tested. The reaction conditions were optimized. Under the selected conditions, the yield of riboflavin was over 92%, which was more than the reported data in reference. The new purification of riboflavin was investigated, the new purification technics was operation simply, high yield and purity.